Electronic Components Datasheet Search |
|
MAX3774 Datasheet(PDF) 7 Page - Maxim Integrated Products |
|
MAX3774 Datasheet(HTML) 7 Page - Maxim Integrated Products |
7 / 9 page Loop Filter, VCO, and Latch The phase detector and frequency detector outputs are summed into a loop filter. An external capacitor (between CF+ and CF-) is required to set the PLL damping factor. The fully integrated VCO contains an internal current reference and filter circuitry to minimize the influence of VCC noise. The VCO creates a clock output with frequency proportional to the control volt- age applied by the loop filter. Data recovery is accom- plished by using the recovered clock signal to latch the incoming data to the CML output buffers, significantly reducing output jitter. LOCK Output An active high LOCK output monitor derived from the frequency detector indicates that the PLL is frequency- locked onto the input data. Without input data, the LOCK signal may settle high or low. The use of a low- pass RC filter is recommended to reduce the effects of chatter that could be caused by high input-jitter con- tent. For optimum jitter performance, keep the load ≥ 15kΩ on the output of the LOCK pin. RATESEL Input The RATESEL input is used to select between input data rates of 2.125Gbps and 1.0625Gbps. This func- tion allows the repeater to sample data at the correct data rate by selecting a divide-by-2 network, giving maximum jitter tolerance at both data rates. The loop bandwidth of the repeater scales with the selected fre- quency; i.e., the loop-bandwidth at an input rate of 1.0625Gbps is half that at the input rate of 2.125Gbps. See the Applications Information section for the func- tionality of the RATESEL pin. Applications Information Input and Output Terminations Figures 3 and 4 show models for the MAX3772– MAX3775 inputs and outputs, including packaging parasitics. Dual-Rate Fibre Channel Repeaters _______________________________________________________________________________________ 7 ESD STRUCTURES IN+ PACKAGE 1.5nH 1.5nH 0.2pF 0.4pF 0.4pF VCC - 0.450V 0.2pF OPTIONAL 50 Ω OR 75Ω 1k Ω VCC Figure 3. Input Structure IN+ IN- LOOP FILTER VCO ÷2 1 0 OUT+ OUT- VCC CLK+ CLK- LOCK VCC DQ RATESEL CLKEN CF+ CF- 0.047 µF PHASE/FREQ DETECTOR OPTIONAL 50 Ω OR 75Ω OPTIONAL 100 Ω OR 150Ω TERMINATION Figure 2. Block Diagram |
Similar Part No. - MAX3774 |
|
Similar Description - MAX3774 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.COM |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |